Pumping device for liquids

ABSTRACT

A liquid pump is housed within a sealed tank. The tank is internally charged with an inert gas and maintained at a pressure exceeding the pressure of the liquid developed by the pump.

Umted States Patent 11 1 1111 3,837,766 Cook Sept. 24, 1974 [54] PUMPING DEVICE FOR LIQUIDS illidmeier 417/982 X 415 20 UX lnvemofi Jerry C00, Darlmgto" 3,309,009 3/1967 417/902 Crystal Lake, 60014 3,746,472 7/1973 Rupp 417/9 [22] Filed: Sept. 4, 1973 P E C J H rlmary xammerusar [21] App!" Assistant Examiner-Richard E. Gluck Attorney, Agent, or FirmKenneth T. Snow [52] US. Cl 417/414, 415/175, 417/902 [51] Int. Cl. F04b 17/00, F04b 35/04 57 ABSTRACT [58] Field of Search 417/313, 414, 421, 902,

7 53; 415 75 A hquld pump 15 housed unthm a sealed tank. The

tank 15 mternally charged wlth an mert gas and mam- [56] References Cited tained at a pressure exceeding the pressure of the liq- UNITED STATES PATENTS devebped by the Pump- 2,911,919 11/1959 Tucker 417/414 3 Claims, 2 Drawing Figures HIH // ll/Il/A/l/ PUMPING DEVICE FOR LIQUIDS BACKGROUND OF THE INVENTION 1. Field of the Invention Certain liquids, such as refrigerants, are costly and their unwarranted escape is expensive. Oftentimes the pumping device is the point of liquid leaking and if that liquid is a refrigerant under pressure, when it escapes it merely vaporizes and is forever lost. Improvements in pumps are being made to overcome such leaks but the pumps are also becoming more costly and still there is no assurance they will not continue to leak and cause the great damage and expense such leaks bring with them.

The present invention is for the purpose of overcoming the adverse effects of leaking liquid pumps. Here the pump is contained within a sealed vessel which is pressurized internally by an inert gas which fills the vessel in and around the entire pump. The inert gas used is one which if mixed with the liquid being pumped, such as a refrigerant, will not cause contamination of that liquid or have any deleterious effect on the usefulness of the liquid. The gas surrounding the pump is maintained at a pressure exceeding that pressure which the pump generates in the liquid. In effect, the inert pressurized gas prevents liquids in the pump from leakmg.

The sealed pressurized vessel containing the pump is equipped on its outside with connecting lines or conduits which join with the interior to deliver electrical service to a position within the vessel, and to deliver and remove inert gas under pressure to the vessel.

2. Description of the Prior Art A preliminary patent search was made on the subject device and the following patents were considered to be the closest prior art available. Hemphill U.S. Pat. No. 2,510,632; Jones et al. U.S. Pat. No. 3,237,562; I-Iudig U.S. Pat. No. 3,558,018; and Montelius U.S. Pat. No. 3,570,722 all show and describe forms of submersible pumps. These pumps are disposed in outer vessels in which the liquid being pumped fills the vessel and surrounds the pump. All of them lack the concept of sealing a liquid pumping pump by housing the pump in an enclosed vessel filled with a pressurized inert gas.

The patent to Dubsek et al. U.S. Pat. No. 3,635,286 shows a device for pumping liquid sodium. An inert gas under pressure is the means for placing a head on the liquid metal being pumped. Here again applicants concept of sealing a liquid pumping pump by a pressurized inert gas is not present.

SUMMARY OF THE INVENTION A principal object of this invention is to provide a novel sealing means for a liquid pump.

An important object of this invention is to provide a housing arrangement for a liquid pump in which the pump is subjected to an inert gas which is pressurized to an extent exceeding the pressure imposed on the liquid by the pump.

Another important object of this invention is to provide a novel arrangement for pumping a liquid in which the pump and its driving motor are disposed within a sealed vessel which in turn is charged with an inert gas under pressure. The inert gas should be one which will not, if mixed with the liquid being pumped, adversely contaminate that liquid.

Other and further important objects and advantages will become apparent from the disclosures in the following specification and accompanying drawings.

IN THE DRAWINGS FIG. 1 is a transverse sectional view of the liquid pumping device of this invention.

FIG. 2 is a sectional view of the pumping device taken on the line 2--2 of FIG. 1.

AS SHOWN IN THE DRAWINGS The reference numeral indicates generally a tank or vessel which is generally cylindrical in shape and horizontally disposed. The cylinder is provided at its ends with outwardly projecting annular flanges 10a and 10b. An end cap 11 is provided with an outwardly projecting annular flange lla which abuttingly mates with the annular flange 10a of the cylinder. 10. Another end cap 12 is provided with an outwardly projecting annular flange 12a which abuttingly mates with the annular flange 10b of the cylinder 10. The adjoining flanges at both ends may be removably locked together, either with or without intermediate gaskets to effect a sealing of the tank 10 and its end walls 11 and 12. When the end wall or walls are removed, complete access may be had to the interior of the vessel for servicing. The inside of the tank is equipped with a generally horizontally disposed floor 13 which is preferably welded or otherwise fastened as shown at 14 in this position.

An electric motor 15 is mounted on the fixed floor 13. A liquid pump 16 is also mounted on the floor 13 and is positioned closely adjacent the motor 15. The motor is equipped with a drive shaft 17 which is directed toward the pump 16. The pump is equipped with a shaft 18 which is disposed in axial alignment with the motor drive shaft 17. A coupling 18a joins the aligned and generally end abutting shafts l7 and 18 and provides for the transfer of rotation from the motor to the rotor of the pump. A fixed electrical service box 19 is located on the top of the vessel or tank 10 of this invention and by means of an electrical cable (not shown) electricity is carried from the box 19 to the electric motor 15. A supply of electrical enery is delivered to the outside of the service box 19 to power the motor 15.

An input or suction pipe or tube 20 extends through the side of the tank 10 and adjoins the pump 16 by a flexible conduit 21. The suction pipe 20 is preferably welded as shown at 22 in place in the cylindrical side of the vessel 10 to prevent leakage around the entrance of that pipe 20 into the tank 10. The inner end of the flexible pipe 21 is joined at 23 to the input side of the pump 16. A flexible pipe 24 is joined to the pump 16 at 25 and acts to deliver liquid under pressure to a system located outside the tank 10. A fixed, rigid pipe 26 is welded at 27 in the cylindrical wall of the vessel 10 and receives the pumped liquid from the flexible pipe 24.

The vessel 10 is provided with an input pipe 28 for the admission of an inert gas to the interior of the tank. The device also preferably includes a pressure gauge 29 for the purpose of seeing at a glance what the pressure is on the inside of the tank. The gauge 29 is located on the top of the tank for ready visibility. A relief pipe 30 is provided in the vessel 10 to permit escape of a portion of the inert gas if it exceeds some predetermined maximum pressure.

OPERATION OF THE DEVICE In the subject device the liquid pump 16 is contained within the pressurized vessel 10. The pressure in the tank is obtained by an inert gas delivered to the vessel through the pipe 28 on the side thereof. The pressure of the inert gas is greater than the pressure developed in the liquid being pumped by the pump 16. The differential in pressures prevents the liquid from leaking out the pump casing. In effect, the pressure of the inert gas holds the liquid in its pump housing and in the conduits or piping leading to and from the pump within the sealed, pressurized vessel.

It is not intended to mix the inert gas with the liquid being pumped, but the inert gas used is one that may be mixed with the liquid without any adverse effects. The inert gas is generally a non-contaminant. It is with this fact in mind that the safety relief line 30 for the tank 10 is preferably joined to a liquid accumulator (not shown). Thus, when the pressure of the vessel 10 exceeds a desirable limit the relief pipe 30 is automatically opened and relieves that pressure to the accumulator.

The high pressure inert gas is to hold the pump against leaking. But, if the seals in the pump do fall it is possible to quickly determine this from outside the vessel 10 by monitoring the line pressure versus the tank pressure as indicated by the gauge 29. If the line pressure increases and the tank pressure falls slightly it would indicate the gas underpressure is being unwarrantedly admitted to the liquid discharge pipe 26 causing that line pressure to increase. When the observer notices a drop in the pressure differential between the liquid line pressure and the tank pressure it indicates the pump seals should be checked and possibly replaced.

I am aware that various details of construction may be changed without departing from the principles disclosed herein and I do not propose limiting the patent granted hereon otherwise than as necessitated by the appended claims.

What is claimed is:

l. A device for pumping liquid comprising a pump, a vessel for housing said pump, means charging said vessel with an inert gas under pressure, the pressure of said inert gas exceeding the pressure of the liquid developed by said pump, and input and output connecting lines and conduits on said vessel communicating with said pump for effecting operation of said pump and delivery of liquid to and from said vessel.

2. A device as set forth in claim 1 in which said vessel is a horizontally disposed cylinder, said cylinder having removable end walls, a floor fastened within said cylinder for the support of the pump within the cylinder.

3. A device for pumping liquid comprising a pump, a motor driving said pump, a vessel for housing said pump and motor, means charging said vessel with an inert gas under pressure, the pressure of said inert gas exceeding the pressure of the liquid developed by said pump, and input and output connecting lines and conduits on said vessel communicating with said motor and pump for delivering power to said motor and liquid to and from the pump. 

1. A device for pumping liquid comprising a pump, a vessel for housing said pump, means charging said vessel with an inert gas under pressure, the pressure of said inert gas exceeding the pressure of the liquid developed by said pump, and input and output connecting lines and conduits on said vessel communicating with said pump for effecting operation of said pump and delivery of liquid to and from said vessel.
 2. A device as set forth in claim 1 in which said vessel is a horizontally disposed cylinder, said cylinder having removable end walls, a floor fastened within said cylinder for the support of the pump within the cylinder.
 3. A device for pumping liquid comprising a pump, a motor driving said pump, a vessel for housing said pump and motor, means charging said vessel with an inert gas under pressure, the pressure of said inert gas exceeding the pressure of the liquid developed by said pump, and input and output connecting lines and conduits on said vessel communicating with said motor and pump for delivering power to said motor and liquid to and from the pump. 